Parallel Draft Models

The following code configures vLLM to use speculative decoding where proposals are generated by PARD (Parallel Draft Models).

PARD Offline Mode Example

from vllm import LLM, SamplingParams

prompts = ["The future of AI is"]
sampling_params = SamplingParams(temperature=0.8, top_p=0.95)

llm = LLM(
    model="Qwen/Qwen3-8B",
    tensor_parallel_size=1,
    speculative_config={
        "model": "amd/PARD-Qwen3-0.6B",
        "num_speculative_tokens": 12,
        "method": "draft_model",
        "parallel_drafting": True,
    },
)
outputs = llm.generate(prompts, sampling_params)

for output in outputs:
    prompt = output.prompt
    generated_text = output.outputs[0].text
    print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")

PARD Online Mode Example

vllm serve Qwen/Qwen3-4B \
    --host 0.0.0.0 \
    --port 8000 \
    --seed 42 \
    -tp 1 \
    --max-model-len 2048 \
    --gpu-memory-utilization 0.8 \
    --speculative-config '{"model": "amd/PARD-Qwen3-0.6B", "num_speculative_tokens": 12, "method": "draft_model", "parallel_drafting": true}'

Pre-trained PARD weights

amd/pard